Amethacrylic resin, which has a high transparency, is useful as a material for a formed article used in an optical member, a illumination member, a signboard member, a decoration member and the like. However, a methacrylic resin has a glass transition temperature of as low as about 110° C., and thus a formed article comprising that methacrylic resin may have a problem of susceptibility to heat deformation.
It is known that a methacrylic resin may have a high glass transition temperature if it has a high syndiotacticity. Examples of a method for manufacturing a methacrylic resin having a high syndiotacticity can include a method involving anionic polymerization (see Patent Documents 1 and 2). However, since a methacrylic resin having a high syndiotacticity obtained by this method has an inferior formability, a formed article comprising this methacrylic resin tends to have an inferior surface smoothness. It is known that lowering a molecular weight can improve formability, but this may cause another problem that the resulting formed article has decreased mechanical strength. For this reason, a formed article comprising a methacrylic resin having a high syndiotacticity has not yet been available for practical use.